3 Flashcards
Idiopathic Inflammatory Bowel Disease (IBD)
- Crohn disease & ulcerative colitis are chronic relapsing inflammatory disorders
of unknown origin
Idiopathic Inflammatory Bowel Disease (IBD) Etiology Pathogenesis
1- Genetic Predisposition
2- Immunologic Factors: ??failure of immune regulation immune responses are directed against self-antigens of the intestinal againon epithelium or to bacterial antigens. CD4+ cells TH1 cells
3- Microbial Factors: microbes provide the antigenic trigger to a dysregulated immune system
Ulcerative Colitis
Definition
Definition: Chronic inflammatory disease of unknown etiology affecting (limited to) the mucosa and submucosa of any part of the colon.
Ulcerative Colitis
Extraintestinal manifestation , Site، Peak incidence between ages
polyarthritis
- hepatic involvement (pericholangitis & primary sclerosing cholangitis).
melamation fibrosisbileduct
Peak incidence between ages 20 and 30 years.
Site:
-The disease usually starts in the rectum and extends proximally and may involve Is the entire colon (pancolitis). (Does Not involve other areas of GI tract)
- Colonic involvement is continuous, No skip lesions
Ulcerative Colitis
Gross ، Microscopy
The affected parts show:
1- Mucosa: Congested, edematous, with easy bleeding
2- Multiple superficial ulcers common during the active phase.
3- The mucosa between the ulcers may show Pseudopolyps (in chronic phase)
Microscopy: is characterized by
1) Mucosal ulcers extending into the submucosa
2) Crypt abscesses (collections of neutrophils and pus cells in crypt lumina )
3) Submucosa: congested + many neutrophils + diffuse mononuclear leucocytes (there are No granulomas)
4) Pseudopolyps: congested inflamed hyperplastic mucosa bulging upward
5) Mucosal dysplasia may develop in prolonged cases.
6) Fibrosis: Submucosal fibrosis & mucosal atrophy (may occur with healing in
chronic phase)
Ulcerative colitis Clinical Features:، Diagnosis
- attacks of bloody mucoid diarrhea, tenesmus, and lower abdominal colicky pain alternating with asymptomatic interval of months to years.
- Bloody stools are more common with ulcerative colitis than with Crohn disease,
- Extra-intestinal manifestations, are more common with ulcerative colitis
Diagnosis :
flexible Sigmoidoscopy (containing a camera) through the rectum A diagnosis of ulcerative colitis can be confirmed by examining the level and extent of bowel inflammation.
Endoscopic examination and biopsy also aimed at detecting dysplasia for possible prophylactic colectomy.
Ulcerative colitis. Complications
1- Haemorrhage, which may be massive.
2- Precancerous leading to carcinoma of colon (10% at 10 years duration and 30% by 30 years or more)
3- Rarely perforation → pericolonic abscess formation or septic peritonitis
4- Fistula: uncommon 5-Stricture of colon: uncommon
6- Toxic megacolon :
- hypotonic and colonic dilation with potential rupture, and perforation with peritonitis. (Exposure of the muscularis propria and neural plexus to fecal material → may lead to complete shutdown of neuromuscular function).
Inflammation & inflammatory mediators can disturb neuromuscular function leading to colonic dilation
7- Primary sclerosing cholangitis: (fibrosis around common bile duct leading to jaundice)
Crohn Disease another name ()() ,Definition, the peak incidence is
Crohn Disease “Terminal ileitis” or “Regional enteritis”
Definition: Chronic inflammatory disease of unknown etiology affecting any part of the alimentary tract from mouth to anus, but most commonly the terminal ileum. It is characterized by transmural inflammation of the affected part (whole wall inflammation)
- It occurs at any age, from childhood to advanced age, - but the peak incidence is 10-30 years & 50-70 years
Site Crohn Disease
small intestine alone in 30% of cases,
The most common site is the terminal ileum.
2 - of small intestine and colon in 50%,
3- of the colon alone in about 20%.
Crohn Disease Gross, Microscopy
Gross:
1- The diseased bowel segments is sharply demarcated from the intervening normal bowel segments (“skip” lesions).
2- Deep linear ulcers (fissures) with cobblestone pattern: extending into the woman muscle wall to serosa oriented along the axis of the bowel intervening mucosa
3- The intestinal wall is thick (dt transmural edema & inflammation),and rigid getting (due to fibrosis) with narrow lumen,
4- Creeping fat: The mesenteric fat surrounds the inflamed serosal bowel surface In cases with extensive transmural disease,
Microscopy: - Transmural inflammation (affecting the full thickness of wall).
- Chronic nonspecific inflammation with neutrophilic infiltration
- Noncaseating granulomas in 60% of cases (epithelioid cells, giant cells)
- Deep Mucosal ulcers extending into the submucosa to muscle
- Mucosal dysplasia may develop
- Later Fibrosis affects all tissue layers including muscularis propria
Crohn disease Radiography , Clinical Features
Recurrent attacks of diarrhea, colicky abdominal pain, and fever lasting days to weeks, with years of remission
Recurrent right lower quadrant colicky pain (obstruction)
Him with diarrhea (?? Appendicitis)
- Extra-intestinal manifestations.
Radiography : he “string sign,” a thin stream of barium passing through the narrowed lumen of the diseased segment.
Crohn disease Complications
1- Haemorrhage: It is usually mild sometimes massive.
2- Perforation with localized abscess or peritonitis.
3- Fistula formation to adherent loops of bowel, the urinary bladder, vagina, or perianal skin;
4- Malabsorption and loss of weight
5- Intestinal stricture → obstruction,
6- carcinoma of the colon or small intestine is less than that associated with ulcerative colitis.
Acute Appendicitis Etiology
Etiology obstruction of the appendix,
1- Usually in the form of a fecalith → obstructs the proximal lumen → Increased intraluminal pressure → mucosal injury and bacterial invasion
2- in children Lymphoid hyperplasia (60% of cases) often secondary to viral infection
3- Other less common causes as seeds of plants or fruits, ball of pinworms (Oxyurias)
Acute Appendicitis Pathology
Pathology: 1- At early stage:→ Acute catarrhal appendicitis: This is the mildest type:
- Appendix is congested, slightly swollen, with few neutrophils in mucosa & submucosa
Fate: a) May resolve. b) May progress to suppurative
At a later stage: → Acue suppurative appendicitis:
- Appendix is congested and swollen. - Lumen contains pus. - Mucosa is ulcerated.
Excess neutrophils in all layers of wall with, pus cells,
- Serosa shows a fibrinopurulent exudate.
Fate: If not excised (appendicectomy) it may become complicated.
Acue Appendicitis Clinical findings
1- Often start with mild colicky periumblical pain → that subsequently localized to right lower quadrant (→ pain & Rebound tenderness at McBurney’s point)
2- Nausea, vomiting, mild (low grade) fever,
3- Laboratory Test: Neutrophilic leukocytosis (↑TLC) may also present.
4- Abdominal /Pelvic Sonogram
